Field of the Invention
The present invention relates to a support part lubrication structure for a gear member in which an oil groove is recessed in either one face of a support face of a support member and a supported face of the gear member, lubricating oil being capable of flowing in the oil groove, and to a differential device to which the lubrication structure is applied.
Description of the Related Art
As the above support part lubrication structure, for example, an arrangement in which the oil groove is formed from a helical groove is conventionally known (ref. Japanese Patent Application Laid-open No. 9-49557). In the conventional structure, based on the screw pump action of a helical groove accompanying relative rotation between a support face of a differential case (support body) side and a supported face of a differential gear (gear member) side, it is possible to efficiently lubricate parts where the support face and the supported face rotationally slide relative to each other by actively making lubricating oil flow from one end of the oil groove toward the other end.
In the conventional structure, since there is only one helical groove provided in the supported face, there is the problem that said one helical groove can exhibit a screw pump action only when there is rotation in one direction of the differential gear (gear member) corresponding to the helical direction of the groove.
In order to solve this problem, providing two helical grooves facing in opposite directions to each other in the supported face could be considered, but in this case if the two helical grooves facing in opposite directions intersect each other partway along, turbulence will occur in the flow of lubricating oil flowing in one oil groove in the section where they intersect, a smooth screw pump action will be inhibited, and this will thus be a main factor in degradation of the lubrication efficiency.